What is a synonym for the term 'caustic'?

The term 'caustic' refers to a type of sharp or biting remark, often characterized by irony or sarcasm. This makes 'sarcastic' a fitting synonym, as both terms convey a sense of scorn or derision through clever or cutting comments. When someone uses caustic language, they are often aiming to criticize or mock someone or something in a way that can be piercing or harsh.

The other options do not align with the meaning of 'caustic.' For example, 'sympathetic' suggests a sense of understanding or compassion, which contrasts sharply with the cutting nature of caustic remarks. 'Crusader' refers to someone who actively campaigns for a cause, lacking the critical tone associated with caustic speech. Lastly, 'foamy' deals with a physical characteristic of substances rather than a manner of speaking, thus being unrelated to the emotional or communicative connotation of 'caustic.'